In vitro cytotoxicity and induction of apoptosis by multiwalled carbon nanotubes in human peripheral lymphocytes: Correlation with physicochemical properties

Multiwalled carbon nanotubes (MWCNTs) consist of more than 80% of the current nanomaterials’ applications worldwide. Despite their wide application, little information is known concerning their impact on human health. The current study aims to identify the in vitro effects of exposure of the human peripheral blood lymphocytes (PBL) to MWCNTs and the possible associations with their physiochemical properties. Two doses (50 and 500 µg/ml) of four different commercially available MWCNTs (obtained from Frascati Laboratory, Sigma Co., Sun Nanotech Co. and Shenzhen Co.) were used in this study. Cell viability and apoptotic activity were evaluated by trypan blue exclusion test and Annexin-V/PI staining in peripheral blood leukocytes (PBL). Physicochemical properties of the different MWCNTs were determined and correlated with the cytotoxicity results after exposure for 12 and 48 h. Results indicate that PBL exposed to MWCNTs showed decreased cell viability and increased apoptosis in a dose- and time-dependent manner. The Pearson’s correlation test showed a lack of relationship between diameter of nanoparticles and their pro-apoptotic activity (r2= 0.282), whereas significant correlations were found between pro-apoptotic activity and the presence of some metal contaminants such as nickel, cobalt and gold (r2= 0.919, 0.698 and 0.520, respectively). Our results therefore suggest that carbon nanotubes at high concentrations lowered cell viability in vitro and induced apoptosis in human cells in vitro. In addition, the results indicate that metal contaminants in carbon nanotubes may be causative of some of the adverse outcomes observed. Finally, our finding provides important information on the biohazard potential of some carbon nanotubes in humans.Key words: Multiwalled, carbon, nanotubes, cytotoxicity, apoptosis, flow cytometry, viability,  lymphocytes

SYNERGISTIC ANTIOSTEOPOROTIC EFFECT OF LEPIDIUM SATIVUM AND ALENDRONATE IN GLUCOCORTICOID-INDUCED OSTEOPOROSIS IN WISTAR RATS

Bisphosphonates (BP) therapy is a vital option to reduce the risk of bone fracture in people who have osteoporosis. However, Bisphosphonate have displayed several side effects. Lepidium sativum (LS) plant and seeds has been used in traditional folk medicine as a mediator for bone fractures. Therefore, we aimed to compare the biochemical effects of LS alone (2% LS in diet, n=8), BP (Alendronate, 70 mg/kg s.c.; n=8) alone, or LS and BP combined in a rat model of glucocorticoid-induced osteoporosis (GIO) by injecting methylprednisolone 3.5 mg/kg per day for 4 weeks. Serum calcium (Ca), albumin, phosphorus (PO4), bone-specific alkaline phosphatase (b-ALP), and tartrate-resistant acid phosphatase (TRAP) were measured 4 weeks after induction of GIO. GIO-group showed significantly increased serum TRAP and decreased b-ALP. GIO-group also showed significantly decreased serum PO4 and unaltered Ca concentrations. Histological examination of GIO-group tibia bones indicates an osteoporotic changes and a concomitant decrease in percentage of trabecular area/bone marrow area (PTB) in the proximal femoral epiphysis. Treatment with either LS and/or BP ameliorated the above mentioned changes with variable degrees; with a net results of enhanced serum calcium, bone architecture, PTB, b-ALP and decreased TRAP in LS and LS+BP groups compared to that of animals treated with Alendronate alone. In conclusion, our findings present evidence supporting the potential benefits of LS in reducing the burden of GCs on bone health

Chemosensetizing and cardioprotective effects of resveratrol in doxorubicin- treated animals

BACKGROUND: Doxorubicin (DOX), an anthracycline antibiotic is one of the most effective anticancer drug used in the treatment of variety of cancers .Its use is limited by its cardiotoxicity. The present study was designed to assess the role of a natural product resveratrol (RSVL) on sensitization of mammary carcinoma (Ehrlich ascites carcinoma) to the action of DOX and at the same time its protective effect against DOX-induced cardiotoxicity in rats. METHODS: Ehrlich ascites carcinoma bearing mice were used in this study. Percent survival of tumor bearing mice was used for determination of the Cytotoxic activity of DOX in presence and absence of RSVL. Uptake and cell cycle effect of DOX in tumor cells in the presence of RSVL was also determined. Histopatholgical examination of heart tissues after DOX and/or RSVL therapy was also investigated. RESULTS: DOX at a dose level of 15 mg/kg increased the mean survival time of tumor bearing mice to 21 days compared with 15 days for non tumor-bearing control mice. Administration of RSVL at a dose level of 10 mg/kg simultaneously with DOX increased the mean survival time to 30 days with 70% survival of the tumor-bearing animals. RSVL increased the intracellular level of DOX and there was a strong correlation between the high cellular level of DOX and its cytotoxic activity. Moreover, RSVL treatment showed 4.8 fold inhibition in proliferation index of cells treated with DOX. Histopathological analysis of rat heart tissue after a single dose of DOX (20 mg/kg) showed myocytolysis with congestion of blood vessels, cytoplasmic vacuolization and fragmentation. Concomitant treatment with RSVL, fragmentation of the muscle fiber revealed normal muscle fiber. CONCLUSION: This study suggests that RSVL could increase the cytotoxic activity of DOX and at the same time protect against its cardiotoxicity

A unique population of effector memory lymphocytes identified by CD146 having a distinct immunophenotypic and genomic profile

<p>Abstract</p> <p>Background</p> <p>CD146 is a well described homotypic adhesion molecule found on endothelial cells and a limited number of other cell types. In cells from the peripheral circulation, CD146 has also been reported to be on activated lymphocytes <it>in vitro </it>and <it>in vivo</it>. The function associated with CD146 expression on lymphoid cells is unknown and very little information is available concerning the nature of CD146+ lymphocytes. In the current study, lymphocytes from healthy donors were characterized based upon the presence or absence of CD146 expression.</p> <p>Results</p> <p>CD146 was expressed on a low percentage of circulating T lymphocytes, B lymphocytes, and NK cells in healthy individuals. CD146 expression can be induced and upregulated <it>in vitro </it>on both B cells and T cells, but does not correlate with the expression of other markers of T cell activation. CD146 positive T cells do not represent clonal expansions as determined with the use of anti Vβ reagents. Data suggest that CD146 positive cells have enhanced adherence to endothelial monolayers in vitro. Gene profiling and immunophenotyping studies between CD146+ and CD146- T cells revealed several striking genotypic distinctions such as the upregulation of IL-8 and phenotypic differences including the paucity of CCR7 and CD45RA among CD146 positive T cells, consistent with effector memory function. A number of genes involved in cell adhesion, signal transduction, and cell communication are dramatically upregulated in CD146+ T cells compared to CD146- T cells.</p> <p>Conclusion</p> <p>CD146 appears to identify small, unique populations of T as well as B lymphocytes in the circulation. The T cells have immunophenotypic characteristics of effector memory lymphocytes. The characteristics of these CD146+ lymphocytes in the circulation, together with the known functions in cell adhesion of CD146 on endothelial cells, suggests that these lymphocytes may represent a small subpopulation of cells primed to adhere to the endothelium and possibly extravasate to sites of inflammation.</p

Human mesenchymal stem cells exert potent antitumorigenic effects in a model of Kaposi's sarcoma

Emerging evidence suggests that both human stem cells and mature stromal cells can play an important role in the development and growth of human malignancies. In contrast to these tumor-promoting properties, we observed that in an in vivo model of Kaposi's sarcoma (KS), intravenously (i.v.) injected human mesenchymal stem cells (MSCs) home to sites of tumorigenesis and potently inhibit tumor growth. We further show that human MSCs can inhibit the in vitro activation of the Akt protein kinase within some but not all tumor and primary cell lines. The inhibition of Akt activity requires the MSCs to make direct cell–cell contact and can be inhibited by a neutralizing antibody against E-cadherin. We further demonstrate that in vivo, Akt activation within KS cells is potently down-regulated in areas adjacent to MSC infiltration. Finally, the in vivo tumor-suppressive effects of MSCs correlates with their ability to inhibit target cell Akt activity, and KS tumors engineered to express a constitutively activated Akt construct are no longer sensitive to i.v. MSC administration. These results suggest that in contrast to other stem cells or normal stromal cells, MSCs possess intrinsic antineoplastic properties and that this stem cell population might be of particular utility for treating those human malignancies characterized by dysregulated Akt

Levels and Determinants of Inflammatory Biomarkers in a Swiss Population-Based Sample (CoLaus Study)

OBJECTIVE: to assess the levels and determinants of interleukin (IL)-1β, IL-6, tumour necrosis factor (TNF)-α and C-reactive protein (CRP) in a healthy Caucasian population. METHODS: population sample of 2884 men and 3201 women aged 35 to 75. IL-1β, IL-6 and TNF-α were assessed by a multiplexed particle-based flow cytometric assay and CRP by an immunometric assay. RESULTS: Spearman rank correlations between duplicate cytokine measurements (N = 80) ranged between 0.89 and 0.96; intra-class correlation coefficients ranged between 0.94 and 0.97, indicating good reproducibility. Among the 6085 participants, 2289 (37.6%), 451 (7.4%) and 43 (0.7%) had IL-1β, IL-6 and TNF-α levels below detection limits, respectively. Median (interquartile range) for participants with detectable values were 1.17 (0.48-3.90) pg/ml for IL-1β; 1.47 (0.71-3.53) pg/ml for IL-6; 2.89 (1.82-4.53) pg/ml for TNF-α and 1.3 (0.6-2.7) ng/ml for CRP. On multivariate analysis, greater age was the only factor inversely associated with IL-1β levels. Male sex, increased BMI and smoking were associated with greater IL-6 levels, while no relationship was found for age and leisure-time PA. Male sex, greater age, increased BMI and current smoking were associated with greater TNF-α levels, while no relationship was found with leisure-time PA. CRP levels were positively related to age, BMI and smoking, and inversely to male sex and physical activity. CONCLUSION: Population-based levels of several cytokines were established. Increased age and BMI, and to a lesser degree sex and smoking, significantly and differentially impact cytokine levels, while leisure-time physical activity has little effect

Levels and Determinants of Inflammatory Biomarkers in a Swiss Population-Based Sample (CoLaus Study)

OBJECTIVE: to assess the levels and determinants of interleukin (IL)-1β, IL-6, tumour necrosis factor (TNF)-α and C-reactive protein (CRP) in a healthy Caucasian population. METHODS: population sample of 2884 men and 3201 women aged 35 to 75. IL-1β, IL-6 and TNF-α were assessed by a multiplexed particle-based flow cytometric assay and CRP by an immunometric assay. RESULTS: Spearman rank correlations between duplicate cytokine measurements (N = 80) ranged between 0.89 and 0.96; intra-class correlation coefficients ranged between 0.94 and 0.97, indicating good reproducibility. Among the 6085 participants, 2289 (37.6%), 451 (7.4%) and 43 (0.7%) had IL-1β, IL-6 and TNF-α levels below detection limits, respectively. Median (interquartile range) for participants with detectable values were 1.17 (0.48-3.90) pg/ml for IL-1β; 1.47 (0.71-3.53) pg/ml for IL-6; 2.89 (1.82-4.53) pg/ml for TNF-α and 1.3 (0.6-2.7) ng/ml for CRP. On multivariate analysis, greater age was the only factor inversely associated with IL-1β levels. Male sex, increased BMI and smoking were associated with greater IL-6 levels, while no relationship was found for age and leisure-time PA. Male sex, greater age, increased BMI and current smoking were associated with greater TNF-α levels, while no relationship was found with leisure-time PA. CRP levels were positively related to age, BMI and smoking, and inversely to male sex and physical activity. CONCLUSION: Population-based levels of several cytokines were established. Increased age and BMI, and to a lesser degree sex and smoking, significantly and differentially impact cytokine levels, while leisure-time physical activity has little effect